Fix: Fixed ZPA Policy Set Controller omitempty tags for slice attributes

[willguibr]

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[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 57.74%. Comparing base (ff44945) to head (22740c7).

Additional details and impacted files

@@            Coverage Diff             @@
##           master     #264      +/-   ##
==========================================
- Coverage   58.22%   57.74%   -0.49%     
==========================================
  Files         173      151      -22     
  Lines        6514     5938     -576     
==========================================
- Hits         3793     3429     -364     
+ Misses       2186     2039     -147     
+ Partials      535      470      -65     

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